Lung cancer type
Location in the lung
Features
Adenocarcinoma (38%)
Peripheral
Most common type of lung cancer in nonsmokers and morecommon in women
Arises from small airway epithelial and type II alveolar cells
Should test for EGFR mutation for possible targeted therapy
Sometimes appear at site of scarring
Tend to form glands and secrete mucin
Squamous cell carcinoma (20%)
⅔ central
⅓ peripheral
Strongly associated with cigarette smoking
Arises from large (proximal) airway epithelial cells
Tend to create obstruction and cause distal atelectasis
Intrathoracic spread rather than distant metastasis; therefore, best prognosis
Small-cell lung carcinoma (SCLC) (14%)
Central (endobronchial)
Neuroendocrine cells are located at bifurcation of small airways
Strongest smoking association
Arises from pulmonary neuroendocrine cells, which are responsible for making neurotransmitters, growth factors, and vasoactive substances
Causes paraneoplastic syndrome: commonly secrete ADH (SIADH) or ACTH (ectopic Cushing syndrome)
Rapid growth and early distant metastasis (brain, liver, bone), leading to the worst prognosis
Large cell carcinoma (3-5%)
Peripheral
Behave similar to adenocarcinomas but the lesions formed tend to be somewhat larger